System and method for administering light therapy

ABSTRACT

A sleep mask is configured to provide light therapy to a subject. The sleep mask may provide a comfortable delivery mechanism for the light therapy, and may deliver the light therapy to the subject while the subject is asleep, in the process of going to sleep, and/or waking from sleep. In one embodiment, the sleep mask includes one or more of a shield, a strap, a first lighting module, and/or a second lighting module.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional application Ser.No. 61/141,292 filed Dec. 30, 2008, which is incorporated herein byreference.

This application is related to U.S. Patent Application Ser. No.61/141,273, entitled “SYSTEM AND METHOD FOR PROVIDING LIGHT THERAPY TO ASUBJECT,” and filed Dec. 30, 2008, and U.S. Patent Application Ser. No.61/141,274 entitled “SYSTEM AND METHOD FOR PROVIDING LIGHT THERAPY TO ASUBJECT,” and filed Dec. 30, 2008, and U.S. Patent Application Ser. No.61/141,289 entitled “SYSTEM AND METHOD FOR ADMINISTERING LIGHT THERAPY,”filed Dec. 30, 2008, and U.S. Patent Application Ser. No. 61/141,295entitled “SYSTEM AND METHOD FOR ADMINISTERING LIGHT THERAPY,” filed Dec.30, 2008, and U.S. Patent Application Ser. No. 61/152,028 entitled“SYSTEM AND METHOD FOR PROVIDING LIGHT THERAPY TO A SUBJECT,” filed Feb.12, 2009, which are hereby incorporated into this application in itsentirety.

The invention relates to the administration of light therapy to asubject.

The direction of radiation on a subject to impact the Circadian rhythmsand/or to address light deficient disorders of the subject are known.Generally, these treatments involve shining light directly towards apatient's eyes while the patient is awake to alleviate or cure lightdeficient disorders including Seasonal Affective Disorder (SAD),circadian sleep disorders and circadian disruptions associated withjet-lag, and shift-work.

There are two types of light therapy devices presently available. Onetype of device is large in size and floor or desk mountable. Thesedevices include light sources of fluorescent bulbs or large arrays oflight emitting diodes. Although they can be moved from one position toanother, they are not generally portable and require a scheduled timeperiod of being stationary during the active part of the day. Inaddition, the light source is quite fragile. The second kind of lighttherapy device is head mountable. These devices are formed as eyeglassesor visors. While they are portable, they are not generally accepted bypatients for use in public because of their odd appearance when worn onthe head. These devices generally lack features that enable them to beused while functioning during sleep. This second type of device mostlyused focused or non-diffuse light sources to direct high luminance lighttowards the eyes.

Further, the lights are positioned to emit beams of light at the eyes ofthe patient while the patient is awake. This approach may impact thecomfort of the treatment to the subject.

One aspect of the invention relates to a system configured to providelight therapy to a subject as the subject sleeps. In one embodiment, thesystem comprises one or more lighting modules, one or more sensors, anda processor. The one or more lighting modules are configured to provideradiation to the eyes of the subject. The one or more sensors areconfigured to generate one or more output signals that conveyinformation related to the position of the eyelids of the subject. Theprocessor is configured to receive the one or more output signalsgenerated by the one or more sensors, and to control the one or morelighting modules such that the one or more lighting modules provideradiation to the eyes of the subject at an intensity level that isdetermined based on the position of the eyelids of the subject.

Another aspect of the invention relates to a method of providing lighttherapy to a subject as the subject sleeps. In one embodiment, themethod comprises providing radiation to the eyes of the subject at afirst intensity; determining information related to the position of theeyelids of the subject; and adjusting the intensity of the radiationprovided to the eyes of the subject based on the position of the eyelidsof the subject.

Another aspect of the invention relates to a system configured toprovide light therapy to a subject as the subject sleeps. In oneembodiment, the system comprises means for providing radiation to theeyes of the subject at a first intensity; means for adjusting theintensity of the radiation provided to the eyes of the subject based onthe position of the eyelids of the subject; and means for adjusting theintensity of the radiation provided to the eyes of the subject based onthe position of the eyelids of the subject.

Another aspect of the invention relates to a system configured toprovide light therapy to a subject as the subject sleeps. In oneembodiment, the system comprises one or more lighting modules, one ormore sensors, and a processor. The one or more lighting modules areconfigured to provide radiation to the eyes of the subject. The one ormore sensors are configured to generate one or more output signals thatconvey information about the current sleep stage of the subject. Theprocessor is configured to control the one or more lighting modules suchthat the one or more lighting modules provide radiation to the eyes ofthe subject, wherein the processor varies causes the intensity of thelight provided to the eyes of the subject by the one or more lightingmodules to vary based on the one or more output signals that conveyinformation about the current sleep stage of the subject.

Another aspect of the invention relates to a method of providing lighttherapy to a subject as the subject sleeps. In one embodiment, themethod comprises providing radiation to the eyes of the subject;determining the current sleep stage of the subject; and adjusting theintensity of the radiation directed to the eyes of the subject based onthe current sleep stage of the subject.

Another aspect of the invention relates to a system configured toprovide light therapy to a subject as the subject sleeps. In oneembodiment, the system comprises means for providing radiation to theeyes of the subject; means for determining the current sleep stage ofthe subject; and means for adjusting the intensity of the radiationdirected to the eyes of the subject based on the current sleep stage ofthe subject.

Another aspect of the invention relates to a system configured toprovide light therapy to a subject. In one embodiment, the systemcomprises one or more lighting modules and a processor. The one or morelighting modules are configured to administer visible radiation to thesubject, wherein the radiation administered to the subject comprises afirst portion of the visible radiation and a second portion of thevisible radiation, the first portion of the visible radiation havingwavelengths that fall within a first section of the visible spectrum andthe second portion of the visible radiation having wavelengths that arewithin the visible spectrum but outside of the first section of thevisible spectrum. The processor is configured to control the one or morelighting modules such that the first portion of the visible radiationand the intensity of the second portion of the visible radiation overtime such that the overall intensity of the administered visibleradiation remains relatively fixed.

Another aspect of the invention relates to a method of providing lighttherapy to a subject. In one embodiment, the method comprisesadministering visible radiation to the subject, wherein the radiationadministered to the subject comprises a first portion of the visibleradiation and a second portion of the visible radiation, the firstportion of the visible radiation having wavelengths that fall within afirst section of the visible spectrum and the second portion of thevisible radiation having wavelengths that are within the visiblespectrum but outside of the first section of the visible spectrum; andvarying the intensity of the first portion of the visible radiation andthe intensity of the second portion of the visible radiation over timesuch that the overall intensity of the administered visible radiationremains relatively fixed.

Another aspect of the invention relates to a system configured toprovide light therapy to a subject. In one embodiment, the systemcomprises means for administering visible radiation to the subject,wherein the radiation administered to the subject comprises a firstportion of the visible radiation and a second portion of the visibleradiation, the first portion of the visible radiation having wavelengthsthat fall within a first section of the visible spectrum and the secondportion of the visible radiation having wavelengths that are within thevisible spectrum but outside of the first section of the visiblespectrum; and means for varying the intensity of the first portion ofthe visible radiation and the intensity of the second portion of thevisible radiation over time such that the overall intensity of theadministered visible radiation remains relatively fixed.

These and other objects, features, and characteristics of the presentinvention, as well as the methods of operation and functions of therelated elements of structure and the combination of parts and economiesof manufacture, will become more apparent upon consideration of thefollowing description and the appended claims with reference to theaccompanying drawings, all of which form a part of this specification,wherein like reference numerals designate corresponding parts in thevarious figures. In one embodiment of the invention, the structuralcomponents illustrated herein are drawn to scale. It is to be expresslyunderstood, however, that the drawings are for the purpose ofillustration and description only and are not a limitation of theinvention. In addition, it should be appreciated that structuralfeatures shown or described in any one embodiment herein can be used inother embodiments as well. As used in the specification and in theclaims, the singular form of “a”, “an”, and “the” include pluralreferents unless the context clearly dictates otherwise.

FIG. 1 illustrates a sleep mask configured to provide light therapy to asubject, in accordance with one embodiment of the invention.

FIG. 2 illustrates a sleep mask configured to provide light therapy to asubject, in accordance with one embodiment of the invention.

FIG. 3 illustrates a sleep mask configured to provide light therapy to asubject, in accordance with one embodiment of the invention.

FIG. 4 illustrates a schematic representation of a sleep mask configuredto provide light therapy to a subject, in accordance with one embodimentof the invention.

FIG. 5 illustrates a schematic representation of a sleep mask configuredto provide light therapy to a subject, in accordance with one embodimentof the invention.

FIG. 6 illustrates a method of providing light therapy to a subject,according to one embodiment of the invention.

FIG. 7 illustrates a system configured to provide light therapy to asubject, according to one embodiment of the invention.

FIG. 8 illustrates a method of providing light therapy to a subject,according to one embodiment of the invention.

FIGS. 1-3 illustrate a sleep mask 10 configured to provide light therapyto a subject. Sleep mask 10 may provide a comfortable delivery mechanismfor the light therapy, and may deliver the light therapy to the subjectwhile the subject is asleep, in the process of going to sleep, and/orwaking from sleep. In one embodiment, sleep mask 10 includes one or moreof a shield 12, a strap 14, a first lighting module 16, and/or a secondlighting module 18.

As can be seen in FIG. 1, shield 12 is configured to cover the eyes ofthe subject wearing sleep mask 10. In one embodiment, shield 12 includesa first shield portion 20 and a second shield portion 22. First shieldportion 20 is configured to cover a first eye of the subject. Secondshield portion 22 is configured to cover a second eye of the subject. Inorder to comfortably cover the first eye and the second eye of thesubject, first shield portion 20 and second shield portion 22 aresubstantially larger than the ocular openings of the eyes of thesubject.

In one embodiment, first shield portion 20 and second shield portion 22are joined by a connecting shield portion 24. Connecting shield portion24 is configured to rest on at least a portion of the nose of thesubject (e.g., across the bridge of the nose) when the subject iswearing sleep mask 10. In some instances (not shown), connecting shieldportion 24 may be narrower or thicker than the embodiment depicted inFIGS. 1-3.

In one embodiment, shield 12 is formed from flexible materials. Theflexibility of shield 12 may enhance the comfort of shield 12 to thesubject. The side of shield 12 visible in FIG. 3 faces toward thesubject during use. On this side, a base surface 26 substantiallyimpermeable to liquids may be formed. For example, the impermeable basesurface 26 may be formed by a flexible plastic material such aspolycarbonate, polyester, and/or other materials. The impermeability ofbase surface 26 may protect electronic components of sleep mask 10carried within shield 12 from moisture.

In one embodiment, shield 12 includes a cushioning layer 28 disposed onbase surface 26. Cushioning layer 28 is formed from a soft, resilientmaterial. For example, cushioning layer 28 may be formed from foam,foam, fabric/foam laminate, and/or other materials. During use,cushioning layer 28 provides the innermost surface to the subject, andengages the face of the subject. As such, the softness of cushioninglayer 28 provides a cushion for the face of the subject, and enhancesthe comfort of sleep mask 10 to the subject.

As will be appreciated from the foregoing and FIGS. 1-3, during useshield 12 provides a barrier between ambient radiation and the eyes ofthe subject. In one embodiment, shield 12 is opaque, and blocks ambientradiation (at least within the visible spectrum), thereby shielding theeyes of the subject from ambient radiation.

Strap 14 is configured to hold shield 12 in place on the subject. In theembodiments shown in FIGS. 1-3, strap 14 is attached to each of firstshield portion 20 and second shield portion 22, and wraps around thehead of the subject to hold sleep mask 10 in place on the head of thesubject. Strap 14 may be adjustable in length (e.g., to accommodatedifferent sized heads). Strap 14 may be formed from a resilient material(e.g., elastic) that stretches to accommodate the head of the user andholds shield 12 in place. It should be appreciated that the inclusion ofstrap 14 in the embodiments of sleep mask 10 illustrated in FIGS. 1-3 isnot intended to be limiting. Other mechanisms for holding shield 12 inplace on the subject are contemplated. For example, a more elaborateheadgear may be implemented, an adhesive surface may be applied toshield 12 that removably adheres to the skin of the subject to holdshield 12 in place, and/or other mechanisms for holding shield 12 inplace may be implemented.

Referring now to FIG. 3, first lighting module 16 and second lightingmodule 18 are mounted to first shield portion 20 and second shieldportion 22, respectively, on the side of shield 12 that faces toward theface of the subject during use. First lighting module 16 and secondlighting module 18 are backlit, and are configured to emit radiationonto the face of the subject on and/or about the eyes of the subject.The radiation emitted by first lighting module 16 and second lightingmodule 18 has a wavelength (or wavelengths) that have a therapeuticimpact on the subject, when they are delivered in accordance with aneffective light therapy plan. In some instances, the radiation emittedby first lighting module 16 and second lighting module 18 is directedtowards the eyes of the subject in radiation fields having relativelyuniform luminance as perceived by the subject. For example, in oneembodiment, the luminance of the radiation emitted by first lightingmodule 16 and second lighting module 18 varies across the respectiveemitted fields by an amount that is less than or equal to about 100:1for use with eyes open, and less than 10,000:1 for eyes-closedapplications. The size of the uniform field of radiation formed byeither first lighting module 16 or second lighting module 18 maycorrespond to the size of the eye of the subject.

FIG. 4 is a schematic illustration of sleep mask 10, in accordance withone or more embodiments of the invention. As can be seen in FIG. 4, inaddition to one or more of the components shown in FIGS. 1-3 anddescribed above, sleep mask 10 may include one or both of a power source26, electronic storage 28, a user interface 30, one or more sensors 32,and/or a processor 34. In one embodiment, one or more of power source26, electronic storage 28, user interface 30, one or more sensors 32,and/or processor 34 are carried on shield 12 and/or strap 14 of sleepmask 10. In this embodiment, one or more of power source 26, electronicstorage 28, user interface 30, one or more sensors 32 and/or processor34 may be removably attached to shield 12 and/or strap 14, and may bedisconnectable from the rest of sleep mask 10. This will enable powersource 26, electronic storage 28, user interface 30, one or more sensors32 and/or processor 34 to be removed from a given shield 12 and/or strap14, and attached to another shield 12 and/or strap 14, which may bebeneficial if shield 12 and/or strap 14 degrade over time and/or withusage and must be replaced. Similarly, in one embodiment, first lightingmodule 16 and second lighting module 18 are also removable/replaceableon shield 12. Power source 26, electronic storage 28, user interface 30,one or more sensors 32 and/or processor 34 may control operation theradiation sources associated with first lighting module 16 and/or secondlighting module 18, as is discussed below.

Power source 26 provides the power necessary to operation the radiationsources associated with first lighting module 16 and second lightingmodule 18, and/or to power electronic storage 28, user interface 30,and/or processor 34. Power source 26 may include a portable source ofpower (e.g., a battery, a fuel cell, etc.), and/or a non-portable sourceof power (e.g., a wall socket, a large generator, etc.). In oneembodiment, power source 26 includes a portable power source that isrechargeable. In one embodiment, power source 26 includes both aportable and non-portable source of power, and the subject is able toselect which source of power should be used to provide power to sleepmask 10.

In one embodiment, electronic storage 28 comprises electronic storagemedia that electronically stores information. The electronically storagemedia of electronic storage 28 may include one or both of system storagethat is provided integrally (i.e., substantially non-removable) withsleep mask 10 and/or removable storage that is removably connectable tosleep mask 10 via, for example, a port (e.g., a USB port, a firewireport, etc.) or a drive (e.g., a disk drive, etc.). Electronic storage 28may include one or more of optically readable storage media (e.g.,optical disks, etc.), magnetically readable storage media (e.g.,magnetic tape, magnetic hard drive, floppy drive, etc.), electricalcharge-based storage media (e.g., EEPROM, RAM, etc.), solid-statestorage media (e.g., flash drive, etc.), and/or other electronicallyreadable storage media. Electronic storage 28 may store softwarealgorithms, information determined by processor 34, information receivedvia user interface 30, and/or other information that enables sleep mask10 to function properly. Electronic storage 28 may include mediaprovided as a separate component within sleep mask 10. Electronicstorage 28 may include media provided integrally with one or more othercomponents of sleep mask 10 (e.g., processor 34).

User interface 30 is configured to provide an interface between sleepmask 10 and the subject (and/or a caregiver) through which the subject(and/or a caregiver) may provide information to and receive informationfrom sleep mask 10. This enables data, results, and/or instructions andany other communicable items, collectively referred to as “information,”to be communicated between the subject and processor 34. Examples ofinterface devices suitable for inclusion in user interface 30 include akeypad, buttons, switches, a keyboard, knobs, levers, a display screen,a touch screen, speakers, a microphone, an indicator light, an audiblealarm, and a printer. In one embodiment, the functionality of which isdiscussed further below, user interface 30 actually includes a pluralityof separate interfaces, including one interface that is carried on sleepmask 10, and a separate interface provided to view and/or manage storedinformation that has been retrieved from sleep mask 10 (e.g., providedby a host computer to which information from sleep mask 10 can bereceived).

It is to be understood that other communication techniques, eitherhard-wired or wireless, are also contemplated by the present inventionas user interface 30. For example, the present invention contemplatesthat user interface 30 may be integrated with a removable storageinterface provided by electronic storage 28. In this example,information may be loaded into sleep mask 10 from removable storage(e.g., a smart card, a flash drive, a removable disk, etc.) that enablesthe user(s) to customize the implementation of sleep mask 10. Otherexemplary input devices and techniques adapted for use with sleep mask10 as user interface 30 include, but are not limited to, an RS-232 port,RF link, an IR link, modem (telephone, cable or other). In short, anytechnique for communicating information with sleep mask 10 iscontemplated by the present invention as user interface 30.

One or more sensors 32 are configured to generate one or more outputsignals that convey information about the current sleep stage of thesubject. In one embodiment, the current sleep stage of the subject maybe determined from the one or more output signals generated by one ormore sensors 32. Determining the current sleep stage of the subject mayinclude determining if the subject is in REM sleep or non-REM sleep.Determining the current sleep stage of the subject may includedetermining if the subject is in stage 1 sleep, stage 2 sleep, or stage3 sleep. In one embodiment, one or more sensors 32 include one or moreof a sensor configured to generate an output signal that indicates adistance between the eye of the subject and the sensor, a sensorconfigured to generate an output signal that indicates a core bodytemperature, an EEG sensor, and/or other sensors.

Processor 34 is configured to provide information processing and/orsystem control capabilities in sleep mask 10. As such, processor 34 mayinclude one or more of a digital processor, an analog processor, adigital circuit designed to process information, an analog circuitdesigned to process information, a state machine, and/or othermechanisms for electronically processing information. In order toprovide the functionality attributed to processor 34 herein, processor34 may execute one or more modules. The one or more modules may beimplemented in software; hardware; firmware; some combination ofsoftware, hardware, and/or firmware; and/or otherwise implemented.Although processor 34 is shown in FIG. 1 as a single entity, this is forillustrative purposes only. In some implementations, processor 34 mayinclude a plurality of processing units. These processing units may bephysically located within the same device (e.g., sleep mask 10), orprocessor 34 may represent processing functionality of a plurality ofdevices operating in coordination.

In one embodiment, processor 34 controls first lighting module 16 andsecond lighting module 18 in accordance with a predetermined lighttherapy algorithm. The predetermined light therapy algorithm may dictatethe timing, the intensity, and/or the wavelength of the radiationemitted by first lighting module 16 and second lighting module 18 towardthe face of the subject on or about the eyes of the subject. In oneembodiment, the predetermined light therapy algorithm is stored inelectronic storage 28, and is provided to processor 34 for execution viacontrol of first lighting module 16 and second lighting module 18. Insome instances, one or more aspects of the predetermined light therapyalgorithm may be adjusted or customized for the subject. Adjustmentsand/or customizations to the predetermined light therapy algorithm maybe input to sleep mask 10 via user interface 30. In one embodiment,electronic storage 28 stores a plurality of different predeterminedlight therapy algorithms, and the subject (and/or a caregiver) selectthe predetermined light therapy algorithm that is appropriate for thesubject via user interface 30.

As was mentioned above, in one embodiment, the predetermined lighttherapy algorithm may dictate the timing of the administration ofradiation to the subject by sleep mask 10. As such, in this embodiment,processor 34 includes a clock. The clock may be capable of monitoringelapsed time from a given event and/or of monitoring the time of day.The subject (and/or a caregiver) may be enabled to correct the time ofday generated by the clock of processor 34 via, for example, userinterface 30.

One parameter of the predetermined light therapy algorithm is themagnitude of the intensity of the radiation. In one embodiment,processor 34 is configured to control first lighting module 16 andsecond lighting module 18 to adjust the intensity of the radiationprovided to the subject such that the intensity of the radiation variesbased on the output signals of one or more sensors 32. For example, insome instances, processor 34 may be configured to control first lightingmodule 16 and second lighting module 18 such that the radiation providedto the subject varies based on the current sleep stage of the subject.In such instances, processor 34 may be configured to first determine thesleep stage of the subject, or processor 34 may be configured to adjustthe intensity of the radiation based on the one or more output signalsfrom one or more sensors 32 without making a preliminary determinationas to the sleep stage of the subject.

By way of non-limiting example, in one embodiment, processor 34 isconfigured to control first lighting module 16 and second lightingmodule 18 such that if the one or more output signals generated by oneor more sensors 32 indicate that the subject is in a first, relativelydeep, sleep stage, first lighting module 16 and second lighting module18 provide radiation to the subject at a first intensity. However, ifone or more output signals generated by one or more sensors 32 indicatethat the subject is in a second, lighter, sleep stage, first lightingmodule 16 and second lighting module 18 are controlled to provideradiation to the subject at a second intensity that is lower than thefirst intensity. This may reduce the chance of the radiation waking thesubject while the subject is in the second sleep stage. In oneembodiment, the first sleep stage is non-REM sleep and the second sleepstage is REM sleep.

In one embodiment, processor 34 is configured to control first lightingmodule 16 and second lighting module 18 such that the intensity of theradiation provided to the subject does not rise above a thresholdintensity. The threshold intensity varies based on the detected sleepstage of the subject. During deeper sleep, the threshold is increased asthe subject is less likely to wake due to the radiation. During lightersleep, the threshold is decreased, as the subject will be more likely tobe awoken by the radiation.

In one embodiment, the threshold intensity is customized for thesubject. For example, the subject may be able to adjust the thresholdintensity via user interface 30. Adjustments by the subject to thethreshold intensity may be made on a per sleep stage basis (e.g.,adjusting the threshold intensity for REM sleep and non-REM sleepseparately), or the subject may make a single adjustment to thethreshold intensity that is implemented by processor 34 for across aplurality of sleep stages (e.g., across REM sleep and non-REM sleep).This may enable the subject to increase the threshold intensity if theradiation does not cause awakening, and to decrease the thresholdintensity if the radiation is interfering with sleep.

In one embodiment, adjustments to the threshold intensity are madeautomatically. In this embodiment, as processor 34 monitors thewakefulness of the subject as the radiation is administered to thesubject by first lighting module 16 and second lighting module 18. Forexample, in instances in which processor 34 determines informationrelated to the sleep stages of the subject, this information may bemonitored to determine if the subject is waking during theadministration of radiation. If the information related to the sleepstages of the subject by processor 34 determines that the radiation isdisrupting the sleep of the subject, processor 34 adjusts the thresholdintensity to alleviate this disruption. This adjustment may be made byprocessor 34 on a per sleep stage basis, or as a single adjustment thatis implemented for the intensity threshold across a plurality of sleepstages.

In one embodiment, processor 34 does not determine information relatedto the sleep stages of the subject, but does determine informationrelated to the position of the eyelids of the subject, such as forexample, whether the eyelids of the subject are open or closed (e.g., asdescribed below). In this embodiment, the determination made byprocessor 34 related to the position of the eyelids of the subject maybe used by processor 34 to determine wakefulness (e.g., the subject isdetermined to be awake if the eyelids open), and to adjust the thresholdintensity of the therapy provided by sleep mask 10 if this monitoring ofthe wakefulness of the subject indicates that the therapy is interferingwith sleep.

In one embodiment, adjustments made to the threshold intensity are madeduring a titration session in which processor 34 is capable ofmonitoring the sleep stages and/or wakefulness of the subject (e.g., ina clinical setting). These adjustments are then implemented in a lesssophisticated embodiment of sleep mask 10 wherein processor 34 is notcapable of monitoring the sleep stages and/or wakefulness of thesubject. The adjustments may be communicated to the less sophisticatedembodiment of sleep mask 10 via manual input, wireless communication,wired communication, removable electronic storage media, or otherwisecommunicated to sleep mask 10. In one embodiment, the less sophisticatedembodiment of sleep mask 10 is capable of monitoring the sleep stagesand/or wakefulness of the subject, but not with the same accuracy and/orprecision that the more sophisticated embodiment of sleep mask 10 usedin the titration session is capable of.

In one embodiment, to enhance the control of processor 34 over firstlighting module 16 and second lighting module 18 in the delivery oflight therapy to the subject, one or more sensors 32 include a sensorconfigured to generate an output signal that indicates core bodytemperature. By way of non-limiting example, sleep mask 10 may includeone or two ear buds (not shown) that are configured to be placed in theear canal of the subject. The ear bud may generate an output signal thatconveys information related to the core body temperature of the subject.For instance, the output signal generated by the ear bud may vary as afunction of the temperature within the ear canal and/or other parametersrelated to core body temperature.

The core body temperature of the subject will typically fluctuate withthe sleep stages of the subject. Accordingly, by monitoring the outputsignal of the sensor configured to generate an output signal thatindicates core body temperature, processor 34 may determine informationrelated to the sleep stage of the subject. In one embodiment, thedetermination of core body temperature may be further implemented byprocessor 34 to diagnose one or more possible ailments of the subject.For example, patients suffering from Alzheimer's disease exhibitsymptoms that are similar to those of frontotemporal degeneration,particularly earlier on in the disease life cycle. However, researchsuggests that Alzheimer's patients experience a deregulation ofCircadian rhythms that includes a maximum and/or minimum core bodytemperature that occur at times that are different from otherindividuals (e.g., delayed). In one embodiment, information related tocore body temperature by processor 34 determined from output signalsgenerated by one or more sensors 32 may be implemented to accuratelydiagnose Alzheimer's disease.

In one embodiment, one or more sensors 32 include an EEG sensor (notspecifically shown) configured to generate one or more output signalsthat indicate electrical activity produced by the brain of the subject.The EEG sensor includes one or more electrodes that are applied to thehead of the subject to receive electrical signals emitted by thesubject's brain. The correlation between EEG output signals and sleepstages is known, and these understood relationships can be implementedby processor 34 to determine the sleep stage of the subject, transitionsof the subject between sleep stages, and/or other information related tothe sleeps stages of the subject. In some instances, the inclusion of anEEG sensor in one or more sensors 32 is made in a more sophisticatedembodiment of sleep mask 10 that is implemented in a clinical setting totitrate one or more aspects of the light therapy provided by sleep mask10 to the subject (e.g., as discussed above). However, this does notpreclude the inclusion of EEG electrodes and/or EEG sensors inembodiments of sleep mask 10 that are produced for general consumer use.

As was mentioned above, one or more sensors 32 may include a sensorconfigured to generate an output signal that indicates a distancebetween the sensor and the eye of the subject. FIG. 5 illustrates aschematic representation of an embodiment of a sensor 32 a configured togenerate such an output signal. In the embodiment illustrated in FIG. 5,sensor 32 a includes an emitter 36 and a photosensitive detector 38.

Emitter 36 emits electromagnetic radiation 40 that is directed onto theeye 42 of the subject. Radiation 40 emitted by emitter 36 includeselectromagnetic radiation having a wavelength (or wavelengths) and/or anintensity that does not adversely impact the eye 42 if the eye 42 isopen. For example, in one embodiment, radiation 40 emitted by emitter 36is in the infrared range, and is visually imperceptible to the eye 42.Emitter 36 may include one or more Organic Light Emitting Diodes(“OLEDs”), lasers (e.g., diode lasers or other laser sources), LEDs,directed ambient radiation, and/or other electromagnetic radiationsources. In one implementation, emitter 36 includes one or more infraredLEDs. While, the present invention is by no means limited to the use ofLEDs, other advantages of implementing LEDs as emitter 36 include theirlight weight, compactness, low power consumption, low voltagerequirements, low heat production, reliability, ruggedness, relativelylow cost, and stability. Also they can be switched on and off veryquickly, reliably, and reproducibly. In some instances, sensor 32 a mayinclude one or more optical elements (not shown) to guide, focus, and/orotherwise process radiation emitted by sensor 32 a.

When emitter 36 emits radiation 40 at the eye 42, a portion of radiation40 is reflected by the eye 42, and is returned to sensor 32 a asradiation 44 in FIG. 5. Photosensitive detector 38 is disposed withinsensor 32 a to receive radiation 44 returning to sensor 32 a from theeye 42. Photosensitive detector 38 is configured to generate an outputsignal based on one or more properties of radiation 44 (e.g., intensity,phase, angle of incidence to sensor 32 a and/or photosensitive detector38, a modulation, time of flight etc.). Due to the configuration ofemitter 36 and/or photosensitive detector 38, one or more properties ofradiation 44 upon which the output signal generated by photosensitivedetector 38 is based convey information about the proximity of sensor 32a to the eye 42 (e.g., the distance between sensor 32 a and the eye 42).In one embodiment, photosensitive detector 38 includes a PIN diode. Inother embodiments, other photosensitive devices are employed asphotosensitive detector 38. For instance, photosensitive detector 38 maytake the form of a diode array, a CCD chip, a CMOS chip, aphoto-multiplier tube and/or other photosensitive devices.

From the output signal generated by photosensitive detector 38 aprocessor (e.g., processor 34 shown in FIG. 4 and described above) maydetermine information about the sleep stage and/or wakefulness of thesubject. For example, the distance from sensor 32 a to the eye 42 willbe different while the eyelid of the eye 42 is open than if the eyelidof the eye 42 is closed (due to the thickness of the eyelid tissue).Thus, the processor may determine whether the eye 42 is open or closedfrom the output signal generated by sensor 32 a.

As was discussed above (with respect to FIG. 4), from an output signalconveying information related to whether the eyelid of the eye 42 isopen or closed the processor can determine whether the subject is awakeor asleep. From this information, the processor may adjust the lighttherapy that is administered by a sleep mask that includes sensor 32 a(e.g., sleep mask 10). For example, a threshold intensity of theradiation provided to the eye 42 while the subject is asleep may beadjusted.

In one embodiment, the processor may implement one or moreother/additional controls over the therapeutic radiation administered tothe subject based on the output signal generated by sensor 32 a. Forexample, if the subject opens the eye 42 during light therapy, asubstantial amount of radiation may become incident on the opened eye.This may be uncomfortable for the subject, and may discourage use. Inorder to enhance the comfort of the subject, the processor may controlthe provision of therapeutic radiation to the eye 42 such that radiationis delivered at a first, relatively high, intensity if the output signalgenerated by sensor 32 a is closed, and to deliver radiation at asecond, relatively low intensity if the output signal generated bysensor 32 a indicates that the eye 42 is open. In one embodiment, thesecond intensity may even be zero (or substantially zero), so thatsubstantially no radiation is provided to the eye 42 of the subjectwhile the eye 42 is open.

It will be appreciated that the disclosure of proximity sensor 32 aprovided in FIG. 5 and above is not intended to be limiting. Other typesof proximity sensors capable of detecting a distance from the eye 42 maybe employed without departing from the scope of this disclosure.

In one embodiment, the output signal generated by sensor 32 a isimplemented by the processor to determine information about the sleepstage of the subject. As the subject sleeps, the subject will pass backand forth between REM sleep and non-REM sleep. One of the physiologicalphenomena that characterizes REM sleep is a characteristic range ofmovements of the eyeball underneath the eyelid. By contrast, duringnon-REM sleep, the eyeball is relatively motionless. Othercharacteristics of eyeball movement may also be indicative of sleepstate. For example, slow-rolling eye movements may occur around sleeponset.

The front of an eyeball is not a perfect arc. In particular, the corneatypically bulges out from the generally spherical shape of the eyeball.As such, during REM sleep, the proximity of the eye 42 to sensor 32 awill vary as the cornea of the eye 42 passes below the point on theeyelid of the eye 42 that receives and reflects radiation 40. The outputsignal of sensor 32 a reflects these proximity changes. Thus, theprocessor may be configured to determine information related to thesleep stage of the subject (e.g., whether the subject is in REM sleep ornon-REM, whether the subject is experiencing or has experienced sleeponset, etc.) from the output signal generated by sensor 32 a.

In one embodiment, sensor 32 a includes a plurality of emitters and/ordetectors that direct radiation to a plurality of locations on the eye42. In this embodiment, the output signal generated by sensor 32 a maynot only provide information that indicates movement of the eyeball, butalso the rotational position of the eyeball (based on the bulge of thecornea) and/or the time derivatives of position (e.g., velocity,acceleration, etc.). As an example, sensor 32 a could be duplicated, andeach of sensors could be mounted along a horizontal center plane on themask to measure the distance to the eyelid or eyeball on either side ofthe vertical center plane toward each corner of at least one eye. Thisenables a continuous measure of the horizontal position of the cornea asthe eye rotates. As an additional example, 3 or 4 sensors might be usedpositioned horizontally and vertically around and pointed toward aquadrant or similar zone of the eye, to enable continuous 2 dimensionalrotation position and motion of the cornea above or beneath the eyelid.

FIG. 6 illustrates a method 46 of providing light therapy to a subject.The operations of method 46 presented below are intended to beillustrative. In some embodiments, method 46 may be accomplished withone or more additional operations not described, and/or without one ormore of the operations discussed. Additionally, the order in which theoperations of method 46 are illustrated in FIG. 6 and described below isnot intended to be limiting. In some embodiments, one or more of themethod 46 may be implemented in a sleep mask that is the same as orsimilar to sleep mask 10 (shown in FIGS. 1-4, and described above).However, in some embodiments, method 46 is implemented in systems and/orcontexts that are different than those described above with respect tosleep mask 10.

At an operation 48, light therapy radiation is provided to the eyes ofthe subject as the subject sleeps. The radiation is of an intensityand/or wavelength to have a therapeutic impact on the subject. In oneembodiment, operation 48 is performed by one or more lighting modulesthat are similar to or the same as first lighting module 16 and/orsecond lighting module 18 (shown in FIGS. 3 and 4 and described above).

At an operation 50, information related to the sleep state of thesubject is determined. The information related to the sleep state of thesubject may include a determination of information related to currentsleep stage of the subject and/or a determination as to whether thesubject is asleep or awake. In one embodiment, operation 50 is performedby a processor that is similar to or the same as processor 34 (shown inFIG. 4 and described above) and/or the processor described above withrespect to FIG. 5. The information determined at operation 50 may bedetermined based on one or more output signals that convey informationrelated to the current sleep state of the subject. The one or moreoutput signals may be generated by one or more sensors that are the sameas or similar to one or more sensors 32 (shown in FIG. 4 and describedabove) and/or sensor 32 a (shown in FIG. 5 and described above).

At an operation 52, one or more parameters of the light therapyradiation being delivered to the subject are adjusted based on theinformation determined at operation 50. The one or more parameters ofthe light therapy radiation that are adjusted may include an intensityof the radiation, a threshold intensity of the light therapy, and/orother parameters. In one embodiment, operation 52 is performed by aprocessor that is similar to or the same as processor 34 (shown in FIG.4 and described above) and/or the processor described above with respectto FIG. 5.

At an operation 54, a determination is made as to whether the eyes ofthe subject are open or closed. In one embodiment, operation 54 isperformed by a processor that is similar to or the same as processor 34(shown in FIG. 4 and described above) and/or the processor describedabove with respect to FIG. 5. The determination made at operation 54 ismade based on one or more output signals that convey information relatedto whether the eyes of the subject are open or closed. In oneembodiment, the one or more output signals are generated by one or moresensors that are the same as or similar to one or more sensors 32 (shownin FIG. 4 and described above) and/or sensor 32 a (shown in FIG. 5 anddescribed above).

At an operation 56, the intensity of the light therapy radiation beingdelivered to the eyes of the subject is adjusted based on thedetermination made at operation 54. In particular, if the determinationmade at operation 54 is that the eyes of the subject are closed, thelight therapy radiation may be delivered to the eyes of the subject at afirst, relatively high, intensity. If the determination made atoperation 56 is that the eyes of the subject are open, the light therapyradiation may be delivered to the eyes of the subject at a second,relatively low, intensity. In one embodiment, the second intensity iszero (e.g., substantially no radiation is provided to the eyes of thesubject). Adjusting the intensity of the light therapy radiation fromthe first intensity to the second intensity may include one or more ofpowering down one or more radiation sources, filtering the light therapyradiation, blocking some or all of the light therapy radiation,reflecting some or all of the light therapy radiation, and/orimplementing other techniques for reducing the intensity of the lighttherapy radiation. In one embodiment, operation 56 is performed by aprocessor controlling one or more lighting modules. The processor may bea processor that is similar to or the same as processor 34 (shown inFIG. 4 and described above) and/or the processor described above withrespect to FIG. 5. The one or more lighting modules may include one ormore lighting modules that are the same as or similar to first lightingmodule 16 and second lighting module 18 (shown in FIGS. 3 and 4 anddescribed above).

FIG. 7 illustrates a system 58 configured to provide light therapy to asubject 60. System 58 is configured to enhance the reception of theelectromagnetic radiation provided to subject 60 during light therapy.In one embodiment, system 58 includes a lighting module 62 and aprocessor 64.

Lighting module 62 is configured to deliver electromagnetic radiation tothe subject. In one embodiment, lighting module 62 includes one or bothof first lighting module 16 and/or second lighting module 18 (shown inFIGS. 3 and 4 and described above). In one embodiment, lighting module62 includes one or more radiation sources disposed within a light boxdevice, or some other device configured to deliver radiation to subject60 for light therapy purposes. In one embodiment, lighting module 62 isconfigured to dynamically adjust the wavelength of electromagneticradiation delivered to subject 60. This may include selectivelyfiltering radiation emitted by one or more sources, powering up or downradiation sources that emit light at different wavelengths, and/or othertechniques for dynamically adjusting the wavelength of generatedelectromagnetic radiation.

Processor 64 is configured to provide information processing and/orsystem control capabilities in system 58. As such, processor 64 mayinclude one or more of a digital processor, an analog processor, adigital circuit designed to process information, an analog circuitdesigned to process information, a state machine, and/or othermechanisms for electronically processing information. In order toprovide the functionality attributed to processor 64 herein, processor64 may execute one or more modules. The one or more modules may beimplemented in software; hardware; firmware; some combination ofsoftware, hardware, and/or firmware; and/or otherwise implemented. Inone embodiment, processor 64 is configured to control lighting module 62to adjust the intensity and/or wavelength of the electromagneticradiation that is delivered to subject 60 during light therapy.

During light therapy, in order for subject 60 to receive the therapeuticbenefit of electromagnetic radiation provided to subject 60,photoreceptors on subject 60 must phototransduce the received photons oflight. However, research has shown that at least in some cases thephotoreceptors of a subject adapt over the course of a light therapysession (or a series of sessions), and begin to phototransduce less andless of the therapeutic light.

To address the adaptation of photoreceptors over time, some lighttherapy systems are configured to increase the intensity of thetherapeutic electromagnetic radiation provided to the subject slowlyover time. Other systems address adaptation by modulating the intensityof the delivered radiation up and down during individual therapysessions. Both of these solutions are found to be uncomfortable by somesubjects, which may lead to discontinuation of light therapy. In orderto reduce the adaptation of the photoreceptors of subject 60 over time,processor 64 is configured to control lighting module 62 to modulate thewavelength of radiation delivered to subject 60 during light therapy.

Generally, the therapeutic benefits of light therapy are generated byproviding electromagnetic radiation to subject 60 in the visiblespectrum with a wave length below a therapeutic threshold. In oneembodiment, the therapeutic spectrum is about 580 nm. During lighttherapy, processor 64 controls lighting module 62 to deliver radiationto subject 60 that includes a first portion of visible radiation and asecond portion of visible radiation. The first portion of visibleradiation is the portion of the radiation directed to subject 60 havingwavelengths that are less than the therapeutic threshold. The secondportion of visible radiation is the portion of the radiation directed tosubject 60 having wavelengths that are greater than the therapeuticthreshold. Rather than varying the overall intensity of theelectromagnetic radiation that is delivered to subject 60, processor 64controls lighting module 62 such that the intensities of the firstportion of visible radiation and the second portion of visible radiationare varied, but the overall intensity of the visible radiation remainsrelatively fixed. This modulation of the intensities of the first andsecond portions of the visible radiation may provide some of the samebenefits as simply varying the total intensity of the deliveredradiation without the discomfort to subject 60 associated with thefluctuating total intensity.

FIG. 8 illustrates a method 66 of providing light therapy to a subject.The operations of method 66 presented below are intended to beillustrative. In some embodiments, method 66 may be accomplished withone or more additional operations not described, and/or without one ormore of the operations discussed. Additionally, the order in which theoperations of method 46 are illustrated in FIG. 8 and described below isnot intended to be limiting. In some embodiments, one or more of themethod 66 may be implemented in a sleep mask that is the same as orsimilar to system 58 (shown in FIG. 7, and described above). However, insome embodiments, method 66 is implemented in systems and/or contextsthat are different than those described above with respect to system 58.

At an operation 68, visible radiation is administered to the subject.The visible radiation includes a first portion of the visible radiationand a second portion of the visible radiation. The first portion of thevisible radiation has wavelengths that fall within a first section ofthe visible spectrum. The second portion of the visible radiation haswavelengths that fall within a second section of the visible spectrum.In one embodiment, the first section of the visible spectrum isseparated from the second section of the visible spectrum by atherapeutic threshold. In one embodiment, operation 68 is performed byone or more lighting modules that are the same as or similar to lightingmodule 62 (shown in FIG. 7 and described above).

At an operation 70, the intensity of the first portion of visibleradiation and the intensity of the second portion of visible radiationare varied, or modulated, over time such that the overall intensity ofthe administered visible radiation remains relatively fixed. In oneembodiment, operation 70 is performed by a processor that is the same asor similar to processor 64 (shown in FIG. 7 and described above)controlling one or more lighting modules that are the same as or similarto lighting module 62 (shown in FIG. 7 and described above).

It will be appreciated that the foregoing embodiments may be implementedto provide light therapy to a subject in an enhanced manner. Inparticular, the features of the invention disclosed herein may enhancethe effectiveness of light therapy, the convenience of light therapy tothe subject, the comfort of light therapy, and/or other aspects of lighttherapy.

Light therapy is known to regulate various substances within the humanbody. These substances include, for example, Melatonin and LuteinizingHormone. As such, implementation of the features described herein in amethod of treating a subject to regulate a level of Melatonin and/orLuteinizing Hormone in a therapeutic manner may provide an enhancedtreatment of a Melatonin and/or Luteinizing mediated condition in thatthe treatment may be more effective, more convenient to the subject,more comfortable for the subject, and/or otherwise enhanced for thesubject. By way of non-limiting example, regulating Melatonin levels isknown to be a treatment for seizures, fibromyalgia, seasonal affectivedisorder, bipolar disorder, unipolar depression, bulimia, anorexia,schizophrenia, panic disorder, obsessive compulsive disorder, and/orother conditions and/or ailments. By way of further non-limitingexample, regulating Luteinizing Hormone levels is known to be atreatment for irregular menstruation, irregular ovulation, lack of sexdrive, muscle mass loss, other effects of aging, and/or other ailmentsand/or conditions.

Although the invention has been described in detail for the purpose ofillustration based on what is currently considered to be the mostpractical and preferred embodiments, it is to be understood that suchdetail is solely for that purpose and that the invention is not limitedto the disclosed embodiments, but, on the contrary, is intended to covermodifications and equivalent arrangements that are within the spirit andscope of the appended claims. For example, it is to be understood thatthe present invention contemplates that, to the extent possible, one ormore features of any embodiment can be combined with one or morefeatures of any other embodiment.

What is claimed is:
 1. A system configured to provide light therapy to asubject as the subject sleeps, the system comprising: one or morelighting modules configured to provide visible light to the eyes of thesubject, one or more sensors configured to generate one or more outputsignals that convey information about the current sleep stage of thesubject; and a processor configured to control the one or more lightingmodules such that the one or more lighting modules provide visible lightto the eyes of the subject, wherein the processor causes the intensityof the visible light provided to the eyes of the subject by the one ormore lighting modules to vary based on the one or more output signalsthat convey information about the current sleep stage of the subject,wherein the processor controls the one or more lighting modules suchthat the one or more lighting modules provide visible light at (i) afirst intensity if the one or more output signals indicate that thesubject is experiencing REM sleep, and (ii) a second intensity if theone or more output signals indicate that the subject is experiencingnon-REM deep sleep, and wherein the first intensity is less than thesecond intensity.
 2. The system of claim 1, wherein the one or moresensors comprise a sensor configured to generate output signals thatindicate a distance between the eye of the subject and the sensor. 3.The system of claim 1, wherein the one or more sensors comprise a sensorconfigured to generate output signals that indicate a core bodytemperature.
 4. The system of claim 1, wherein the one or more sensorscomprises an EEG sensor.
 5. A method of providing light therapy to asubject as the subject sleeps, the method comprising: providing visiblelight to the eyes of the subject; determining the current sleep stage ofthe subject; and adjusting the intensity of the visible light directedto the eyes of the subject based on the current sleep stage of thesubject, wherein adjusting the intensity of the visible light directedto the eyes of the subject based on the current sleep stage of thesubject comprises (i) adjusting the intensity of the visible light to afirst intensity if the subject is experiencing REM sleep, and (ii)adjusting the intensity of the visible light to a second intensity ifthe subject is experiencing non-REM deep sleep, and wherein the firstintensity is less than the second intensity.
 6. The method of claim 5,further comprising generating an output signal that indicates a distancebetween the eye of the subject and the sensor, wherein determining thecurrent sleep stage of the subject comprises determining the currentsleep stage of the subject based on the generated output signal.
 7. Themethod of claim 5, further comprising generating output signals thatindicate a core body temperature, wherein determining the current sleepstage of the subject comprises determining the current sleep stage ofthe subject based on the generated output signals.
 8. The method ofclaim 5, further comprising generating one or more output signals thatindicate electrical activity produced by the brain of the subject,wherein determining the current sleep stage of the subject comprisesdetermining the current sleep stage of the subject based on thegenerated output signal.
 9. A system configured to provide light therapyto a subject as the subject sleeps, the system comprising: means forproviding visible light to the eyes of the subject; means fordetermining the current sleep stage of the subject; and means foradjusting the intensity of the visible light directed to the eyes of thesubject based on the current sleep stage of the subject, wherein themeans for adjusting the intensity of the visible light directed to theeyes of the subject based on the current sleep stage of the subjectcomprises (i) means for adjusting the intensity of the visible light toa first intensity if the subject is experiencing REM sleep, and (ii)means for adjusting the intensity of the visible light to a secondintensity if the subject is experiencing non-REM deep sleep, and whereinthe first intensity is less than the second intensity.
 10. The system ofclaim 9, further comprising means for generating output signals thatindicate a distance between the eye of the subject and the sensor,wherein the means for determining the current sleep stage of the subjectcomprises means for determining the current sleep stage of the subjectbased on the generated output signals.
 11. The system of claim 9,further comprising means for generating output signals that indicate acore body temperature, wherein the means for determining the currentsleep stage of the subject comprises means for determining the currentsleep stage of the subject based on the generated output signals. 12.The system of claim 9, further comprising means for generating one ormore output signals that indicate electrical activity produced by thebrain of the subject, wherein the means for determining the currentsleep stage of the subject comprises means for determining the currentsleep stage of the subject based on the generated output signal.